SardiniaChem2008
GIORNATA DI STUDIO DEDICATA ALLA CHIMICA ORGANICA
DELLE MOLECOLE BIOLOGICAMENTE ATTIVE 30 Maggio 2008, Aula Magna della Facoltà di Scienze – Sassari
Comitato Scientifico:
Giampaolo Giacomelli, Univ. Sassari; Giovanna Delogu CNR Sassari; Salvatore Cabiddu, Univ. Cagliari; PierPaolo Piras, Univ. Cagliari
Comitato Organizzatore:
Andrea Porcheddu, Univ. Sassari; Roberto Dallocchio, CNR Sassari; Stefania De Montis Univ. Cagliari
Sponsor
hanno contribuito alla realizzazione del convegno:
UNIVERSITA’ di Sassari-Dipartimento di Chimica; UNIVERSITA’ di Sassari-Facoltà di Scienze MFN; CNR-Istituto di Chimica Biomolecolare, Sassari; UNIVERSITA’ di Cagliari;
SAPIO s.r.l.; SIGMA-ALDRICH s.r.l.; CARLO ERBA Reagenti; MEDINLAB s.r.l.; VWR International s.r.l. NH OH O O O Me OH O Me O O Me OH O O Me O O Me Me H O
P 40 MICROENCAPSULATION OF BACILLUS THURINGIENSIS AND
INSECTICIDAL ACTIVITY EVALUATION ON LARVAE OF LEPIDOPTERA V. Sanna, M.D.L. Moretti
Dipartimento di Scienze del Farmaco, via Muroni 23/A 07100 Sassari
Bacillus thuringiensis (Bt) is one of the bacterial entomopathogens most frequently studied as a toxin producer. Its insecticidal activity was attributed to the parasporal crystals formed during the stationary phase of its growth cycle, and released during sporulation.1 The efficacy of Bt is highly
sensitive to the environmental conditions; when exposed to UV light, the insecticidal proteins undergoes to rapid degradation.
Considerable research has attempted to improve Bt field persistence using ultraviolet absorbers, encapsulation and addition of clay granules to spray formulations.2
The aim of this study was to investigate different encapsulation processes in order to obtain the Bt-based formulations consisting of matrix-type microcapsules.
Gelatin and Sodium Alginate were selected as polymeric materials for the preparation of microcapsules. The obtained systems were characterized in terms of morphology and encapsulation efficiency, and their toxicity on larvae of different insect species (Lymantria dispar, Malacosoma neustrium and Plodia interpunctella) was assessed in vitro.
The results showed that the microencapsulation process by double emulsion technique gave high encapsulation yields (over 95%). Data concerning the larvicidal effects of the examined formulations, expressed as percentage of mortality, suggested that the prepared microcapsules had toxic effects and determined mortality values of about 60% towards selected insect.
Given these encouraging results, further experiments are in progress to assess the suitability of microcapsules for application as a new tool in integrated control of different pest larvae.
1. Schnepf E, Crickmore N, Van Rie J, Lereclus D, Baum J, Feitelson J, Zeigler DR, Dean DH. Bacillus
thuringiensis and Its Pesticidal Crystal Proteins. Microbiology and Molecular Biology Reviews 1998, 775–806. 2. Tamez-Guerra P, McGuire MR, Behle RW, Shasha BS, Galan-Wong LJ. Assessment of microencapsulated
formulations for improved residual activity of Bacillus thuringiensis. J. Econ. Entomol. 2000, 93, 219-225.
